The search for psychophysiological measures related to the psi process has recently been the center of much interest in parapsychology. Studies have been reported relating performance on various types of psi tasks to physiological measures both within and between subjects. This note is not meant to discuss the findings or merits of such studies, but rather to discuss a methodological factor present in some of this type of research.

Two experiments with human Ss explored the paper maze technique devised by W. J. Levy as an analog of devices used in testing the “random behavior” hypothesis of animal psi. Exp I with 72 unselected Ss yielded no evidence of departure from mean chance expectation. Exp II was done with 75 Ss selected individually for interest in psi or probability of exhibiting psi. The departure of the overall hitting rate (50.9%) from mean chance expectation (50%) was significant at the .01 level. The departure from chance was so small that this method is of little promise for the study of factors influencing hitting rate unless ways are found to make the apparent effect larger or more stable; however, possible effects of experimental variables were looked for in the data. Two such variables–dominant vs nondominant hand, and type of psi target–yielded no significant results. Random vs nonrandom behavior showed no significant difference, and the tendency was opposite to that reported in the animal experiments. A type of behavior intermediate between random and nonrandom yielded a post hoc finding suggestive for future research with the maze or other techniques.

Four female Long Evans rats were tested in a psychokinesis experiment in which a bar press in an operant chamber initiated a random generator choice. The hit probability was 1 in 10. A food reward was given for hits. Run length was set at 1,000 trials and the number of runs at five for each rat. The purpose of the study was to replicate an experiment by Sandford (1976) which showed inclines within runs under similar conditions. The present experiment gave declines (t = 2.43, df = 18; p < .05 two tailed).

Heretofore the criticism of the Pratt-Woodruff ESP experiment has been based on the discovery that the significant results were concentrated in those trials made in relation to the key cards that were in the end positions in the preceding run (E-cards). The critics attributed this finding to fraud on the part of one of the experiments on the ground that he must have kept track of those key cards from one run to the next and misplaced cards to those positions to score spurious hits. The experimenters, on the other hand, argued that the E-cards could have been more favorable for ESP success because of the subject’s psychological reaction to them. This paper describes an analysis based upon the E-card trials alone for the highest scoring subject, P.M. It was found that scoring was near the chance level for those E-cards that were not shifted from the positions they occupied in the preceding run and the results were significant only on the shifted E-cards. This finding supports the ESP interpretation of the E-card effect and it is not consistent with the Hansel interpretation of experimenter fraud. Other analyses also support the ESP hypothesis as the explanation of the results of the Pratt-Woodruff experiment.

An experiment was conducted to investigate whether or not an experimenter’s expectancy could be manipulated toward a desired end goal of positive or negative ESP scoring by subjects. A total of six college students acted as experimenters, two in a pilot and four in a confirmatory series. Each experimenter administered a clairvoyance test to a group of 20 subjects. The test consisted of one run of 24 trials, and high frequency words were used as targets. Half of the experimenters were told that the test was highly psi conducive and that they could expect positive scoring from their subjects. The other experimenters were told that the test consistently elicited psi missing and that they could expect only negative scoring. Marginally significant results in the pilot supported the hypothesis that an experimenter’s expectancy can influence the direction of subjects’ ESP scores. In the confirmatory experiment, as predicted, the subjects tested by the experimenters who expected psi hitting scored significantly above chance (p<.01), while those tested by the experimenters who expected psi missing scored significantly below chance (p<.01). A significant difference was found between the two experimenter expectancy groups in both series (p<.01) for the pilot and p<.001 for the confirmation).